<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
<script>
var str="a";
switch (str){
	case 'b':alert(22);break;
	
	case 'a':alert(11);break;

	default:alert(00);

}
</script>
</head>

<body>
</body>
</html>
